The use of electronic pre-distortion (EPD) to compensate chromatic dispersion was proposed as early as two decades ago. (T. L. Koch et al., JLT, vol. 3, 1985, pp. 800-805.) Thanks to progress in high-speed electronic digital signal processing, there has recently been a revived interest in this technique for 10 Gb/s systems. The aim of more recent studies of this technique has been to entirely eliminate inline optical dispersion compensators (ODCs) by compensating chromatic dispersion at the transmitters. (See, e.g., M. M. El Said et al, JLT, vol. 23, 2005, pp. 388-400; D. McGhan et al, OFC'05, paper PDP27; R. I. Killey et al, IEEE PTL, vol 17, 2005, pp. 714-716.)
Due to large temporal power variations in such systems and the absence of nonlinearity compensation through dispersion mapping, nonlinearities in EPD systems are much larger than systems using ODCs. (See R. J. Essiambre et al, OFC'06, paper OWB1; R. J. Essiambre et al, ECOC'05, paper Tu3.2.2.)
Although EPD has the ability, in principle, to compensate self-phase modulation (SPM), inter-channel cross-phase modulation (XPM) greatly impacts EPD systems, especially systems operating at 10 Gb/s. Moreover, operation of EPD at 40 Gb/s increases transmitter complexity considerably due to an increase by a factor of 16 in bit overlap. Alternatively, multi-level modulation formats with advanced receivers have been required when implementing EPD at 40 Gb/s. (P. J. Winzer et al, ECOC'05, paper Tu4.2.2.)